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Alertness
Published in Charles Theisler, Adjuvant Medical Care, 2023
Tyrosine: Taking tyrosine (150 mg/kg) helps people who have lost a night’s sleep stay alert for about three hours longer than they otherwise would.7,8 Also, research studies indicate that tyrosine improves memory and reasoning in people who are sleep-deprived.8
Hepatorenal tyrosinemia/fumarylacetoacetate hydrolase deficiency
Published in William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop, Atlas of Inherited Metabolic Diseases, 2020
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop
The deficient enzyme is on the catabolic pathway for tyrosine, and this is the cause of the hypertyrosinemia (see Figure 22.1). Fumarylacetoacetate accumulates and is converted to succinylacetoacetate and to succinylacetone. In hepatorenal tyrosinemia, concentrations of tyrosine usually range from 170 to 660 μmol/L (3–12 mg/dL).
The Importance of Personalized Nutrition in Psychological Disorders
Published in Nilanjana Maulik, Personalized Nutrition as Medical Therapy for High-Risk Diseases, 2020
Catecholamines (norepinephrine, dopamine and epinephrine) are synthesized from tyrosine by neurons in the brain. Being one of the essential amino acids, L-phenylalanine is the direct precursor of tyrosine; however, the body receives the two through a normal diet. After being formed by tyrosine, dihydroxyphenylalanine (DOPA) is transformed into dopamine, which in return forms norepinephrine and then epinephrine. Neurotransmitters norepinephrine and dopamine are involved in depression. Few studies have investigated whether there is a relationship between tyrosine deficiency and depression (Parker and Brotchie 2011). Nevertheless, plasma concentrations of tryptophan, tyrosine and phenylalanine levels are observed to be lower among individuals with ADHD (Bornstein, Baker et al. 1990).
Predictive serum biomarkers of patients with cerebral infarction
Published in Neurological Research, 2022
Yan Kong, Yu-qing Feng, Ya-ting Lu, Shi-sui Feng, Zheng Huang, Qian-yi Wang, Hui-min Huang, Xue Ling, Zhi-heng Su, Yue Guo
During phenylalanine, tyrosine, and tryptophan biosynthesis, phenylalanine is initially converted into tyrosine in vivo. It has been reported that the increase in phenylalanine in the blood significantly increases abnormalities in electroencephalogram and the occurrence of cerebral ischemia in varying degrees. Moreover, high phenylalanine content can variably aggravate cerebral ischemia and brain damage in children [18–22]. In our study, the content of tyrosine was significantly higher in the patient group than that of the control group. We speculate that this is attributed to the increased content of phenylalanine, which is easily converted into tyrosine and thus, increasing the content of tyrosine. Taken together, the increased serum tyrosine level and the dysfunction of phenylalanine, tyrosine, and tryptophan biosynthesis in cerebral infarction patients may be a cause of cerebral infarction. Moreover, we suggest that treatment of cerebral infarction should aim to reduce phenylalanine.
Metabolomic assessment of mechanisms underlying anti-renal fibrosis properties of petroleum ether extract from Amygdalus mongolica
Published in Pharmaceutical Biology, 2021
Chen Gao, Wan-fu Bai, Hong-bing Zhou, Hai-mei Hao, Ying-chun Bai, Quan-li Liu, Hong Chang, Song-li Shi
l-Tyrosine is a non-essential amino acid and a precursor of various bioactive molecules, including brain catecholamine neurotransmitters including norepinephrine and dopamine (DA) (Wang et al. 2019). DA is an endogenous nitrogen-containing organic compound that is the intermediate product of l-tyrosine biosynthesis from dihydroxyphenylalanine. Gülçin (2007) showed that l-tyrosine scavenged free radicals like DPPH (1,1-diphenyl-2-picrylhydrazyl radical), ABTS, superoxide anion and H2O2, and also reduced ferrous ion chelation. Øvrehus et al. (2019) found that 11 amino acids, including tyrosine, phenylalanine, dopamine, homocysteine and serine, were affected in hypertensive nephrosclerosis patients. This disorder is characterised by a 30–70% decrease in urine output, endothelial dysfunction, atherosclerosis and renal fibrosis due to dysregulated dopamine biosynthesis in the kidney (Zhang 2013).
Distortion product otoacoustic emission sensitivity to different solvents in a population of industrial painters
Published in International Journal of Audiology, 2020
Renata Sisto, Luigi Cerini, Filippo Sanjust, Damiano Carbonari, Monica Gherardi, Andrea Gordiani, Nunziata L’Episcopo, Enrico Paci, Daniela Pigini, Giovanna Tranfo, Arturo Moleti
The oxidative stress and the nitrosative stress are recognised to cause many acute and chronic diseases and even of the physiological aging process. The oxidation process involve DNA, RNA, lipids and proteins. In the proteins usually this process implies the introduction of functional groups that could alter the protein function and metabolism. The tyrosine is an amino acid present in the most part of the proteins. This amino acid is slightly hydrophilic due to the aromatic benzene ring that transport a hydroxyl group. One of the most important biomarker of the protein oxidation is the 3 Nitrotyrosine (3NO2tyrosine), an oxidation product of the tyrosine, that is produced in the reaction of NO or of the NO3 and that represents a damage on proteins and amino acids (Bandookwala et al. 2019). In this paper, the concentration of tyrosine and of its oxidation product 3NO2tyrosine were measured and compared at the beginning and the end of the work-shift. The methylation product of the cytidine, 5-methylcytidine, was also quantified as a measure of the damage to the RNA. The 5-methylcytidine is one of the epigenetic marks of DNA and RNA, and aberrant levels of this modified nucleoside were found to be associated with various cancers (Guo et al. 2018).